Content Of NH4 Research Articles

Multivariate analysis of anion-cation relationships in soil solution in a lysimeter experiment

A lysimeter experiment was conducted for 36 days to determine the content and distribution of ions in a soil solution. Three factors were considered: urine vs. no urine; anion forms, chloride (Cl) vs. sulphate (SO4); and planted vs. bare soil. The results indicate that Cl in the soil solution moved downward more slowly than SO4, and nitrate (NO3) concentration increased at all levels with time. By comparison, monovalent cations (K and NH4) remained in the upper three layers (0-15 cm) and divalent cations (Ca and Mg) in the soil solution moved into the lower layers (10-25 cm) with time. The multiple regression analyses showed that the amount of K present in the soil solution is mainly controlled by the concentration of the anions and NH4 concentration is controlled by Cl and SO4 levels. In addition, K and NH4 contents are regulated by the corresponding exchangeable cation contents. Divalent cations are present in such proportions that electroneutrality is balanced, although their contents are controlled by those of Cl and NO3 to a certain extent. Canonical correlation analysis showed that the 1st two canonical variates are positively and highly correlated with each ion concentration, and are considered to be weighted means of anion and cation concentrations. Summation of the respective anions or cations multiplied by the weights indicated a high correlation among them. This relationship may reflect accurately the electro-neutrality in a soil solution.

Availability of fixed NH4 + to crops

Significantly lower amounts of exchaneable NH4, soluble NO3 and clay-fixed NH4 forms of N were observed in the unfertilized fields with high rather than low-density cropped plots. Irrespective of planting densitites, the fixed NH4 content in soil increased with increase in the period of crop growth. N uptake by plant and total bacterial population of rhizosphere soil were significantly higher in the plots with the high than with the low-density planting. Availability of native fixed NH4+ to crops and biological utilization of a considerable amount of recently mineralized NH4+ in fixed form is indicated.

Inhibitory Effects of Ammoniacal Nitrogen on Growth of Radish Plants. I. Characterization of Toxic Effects of NH4+ on Growth and its Alleviation by NO3−1

Abstract Growth of radish (Raphanus sativus L.) was inhibited by NH4 as the source of N at concentrations from 1 to 240 ppm N. Higher levels of free NH4 accumulated in the plants as a result of NH4 nutrition. Nitrate equivalent to 10% or more of the NH4 concentration alleviated the inhibitor effects of NH4 on growth and also decreased the NH4 content of the plants. Five cultivars of radish responded similarly. Ammonium was also harmful for growth of etiolated seedlings, but NO3 did not reverse the inhibitory effects of NH4.

Stimulation of pancreatic islet metabolism and insulin release by a nonmetabolizable amino acid.

The leucine analog beta-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid (BCH) activates glutamate dehydrogenase [L-glutamate:NAD+ oxidoreductase (deaminating), EC 1.4.1.2] in pancreatic islet homogenates. In intact islets, BCH increased the islet content or output of NH4+, 2-ketoglutarate, malate, pyruvate, and alanine. BCH caused a dose-related increase in 14CO2 output from islets prelabeled with L-[U-14C]glutamine. BCH increased the islet content of ATP and stimulated both 45Ca net uptake and insulin release. The capacity of seven distinct amino acids to activate glutamate dehydrogenase tightly correlated with their ability to augment 14CO2 output from islets prelabeled with [U-14C]-glutamine and to stimulate insulin release in the presence of L-glutamine. The activation of glutamate dehydrogenase by BCH may thus account for the insulin-releasing capacity of the leucine analog.

The significance of gypsum applied to mushroom compost, in particular in relation to the ammonia content.

With gypsum treatment the nitrogen loss in the compost is slightly reduced and the pH is decreased. Curvilinear relationships were established between the NH4 content of the compost at filling and the yield in the presence or absence of gypsum and with or without supplementation with soya bean meal. These curves (four parabolas) give a clear picture of the significance of gypsum under various circumstances. The optimum gypsum treatment was 25 kg per 1000 kg of horse manure. Time of application of the gypsum was not very important, but an early application favoured a more uniform distribution and prolonged its action. The drop in pH caused by gypsum influences the dissociation of NH4+ ions considerably, i.e. in the presence of gypsum less NH3 is present in the compost. A possible mechanism by which gypsum lowers the pH is discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

AMMONIUM EXCHANGE EQUILIBRIA IN THE SUBMERGED SOILS AND FORMS OF AMMONIUM WHICH ARE NOT WATER-SOLUBLE BUT ARE AVAILABLE TO LOWLAND PADDY

In an experiment in the greenhouse, NH4+-(Ca2+ + Mg2+) exchange equilibria were studied for two soils from the equilibrium soil solution. Activity ratios of ammonium, aNH4/aCa + aMg)1/2, when plotted against the changes (±ΔNH4ex) in the exchangeable NH4 content of the soil, gave a linear relationship and obeyed Schofield's ratio law. Submergence markedly increased the equilibrium activity, AR0NH4, from 5.95 x 10-3 to 6.9 x 10-3 M1/2 in Habbel Kher loam. Nearly constant buffering capacity (BCNH4) for Habbel Kher loam (52.5 ± 2.5 me 100–1 g soil M-1/2) and Saleempur sandy loam (68.3 ± 2.8 me 100–1 g soil M-1/2) showed that it is a characteristic property of soil and is independent of such management practices as flooding of paddy soils. A significant relationship between activity ratio and dry matter yield (r = 0.90) and N uptake (r = 0.98) by paddy shows that the ammonium activity ratio gives a fairly good measure of the N nutrition of rice grown under submerged soil conditions. A graphical method for determining forms of ammonium which are not water-soluble but are avdlaile to Icwlajid paddy is proposed. Equilibrium labUe ammonium (NH4EL) and activity ratios of ammonium, aNKH4+/(aCa + aMg)1/2, were calculated and plotted, and the intercept of the Q/I isotherm on the Q axis was determined. The negative value of the intercept showed the capability of the plants to utilize ammonical N even when the concentration of NH4+ in the soil solution is zero (ARNH4 = 0). The value of the intercept as 0.20 (me/100 g soil) can be used as a measure of the amount of these forms of ammonium.

Effects of Calcium Carbonate on Ammonium Assimilation by Tomato Seedlings1

Abstract Seedlings of tomato (Lycopersicon esculentum Mill.) (15 to 22 days old) exposed to unbuffered solutions containing N solely in the NH4 form showed poorly developed, thickened, less branched, discolored root systems, marginal necrosis of some leaves, wilting, particularly dark green foliage, and restricted growth. Calcium carbonate at 0.5 g/liter alleviated NH4 toxicity and restricted the accumulation of free NH4 in roots, bleeding sap, and shoots even though NH4 uptake rates were accelerated by CaCO3. Thus, the beneficial effect was related to enhanced NH4 assimilation. Roots contained an active NADH-specific L-glutamate dehydrogenase, but in vitro activity was correlated with internal NH4 content and, therefore, did not reflect actual NH4 assimilation rates during experimental periods.

Effects of increased mechanical work by isolated perfused rat heart during production or uptake of ketone bodies. Assessment of mitochondrial oxidized to reduced free nicotinamide-adenine dinucleotide ratios and oxaloacetate concentrations

Metabolic effects of increased mechanical work were studied by comparing isolated pumping rat hearts perfused by the atrial-filling technique with aortic-perfused non-pumping hearts perfused by the technique of Langendorff. The initial medium usually contained glucose (11 mm) and palmitate (0.6 mm bound to 0.1 mm albumin). During increased heart work (comparing pumping with non-pumping hearts) the uptake of oxygen and glucose increased threefold, but that of free fatty acids was unchanged. Tissue contents of alpha-oxoglutarate, NH4+, malate, lactate, pyruvate and Pi rose with increased heart work, but contents of ATP, phosphocreatine and citrate fell. Ketone bodies were produced with a ratio of beta-hydroxybutyrate/acetoacetate of about 3:1 in both pumping and non-pumping hearts but with higher net production rates in non-pumping hearts. When ketone bodies were added in relatively high concentrations (total 4 mm) to a glucose (11 mm) medium the medium, ratios of beta-hydroxybutyrate/acetoacetate were not steady even after 60 min of perfusion. The validity of calculating mitochondrial free NAD+/NADH ratios from the tissue contents of the reactants of the glutamate dehydrogenase system or the beta-hydroxybutyrate dehydrogenase system is assessed. The activities of these enzymes are considerably less in the rat heart than in the rat liver, introducing reservations into the application to the heart of the principles used by Williamson et al. (1967) for calculation of mitochondrial free NAD+/NADH ratios of liver mitochondria...

Nitrogen, Salinity, and Acidity Distribution in an Irrigated Orchard Soil as Affected by Placement of Nitrogen Fertilizers

AbstractA field experiment was conducted to determine the vertical and lateral changes in the distribution of nitrogen, salinity, and acidity occurring in an irrigated orchard soil following addition of (NH4)2SO4, NH4NO3, or Ca(NO3)2 by broadcast, in broad band, or in narrow band. The NH4 and NO3 contents in soil decreased rapidly even under narrow band placements. Considerable nitrate movement was observed. After 1 year, neither the total nor the inorganic N level in the fertilized plots was significantly different from that of the control. High salinity was detected under the narrow band placements, but the level diminished rapidly with time. Little salinity was evident under the broad band or broadcast placements. However, the acidity produced by the ammonium fertilizers persisted after 1 year. Changes in soil properties under narrow bands were drastic, whereas changes under broad bands were insignificant.

AMMONIUM FIXATION IN RELATION TO EXCHANGEABLE K AND ORGANIC MATTER CONTENT IN TWO SASKATCHEWAN SOILS

Profile samples from two fine-textured soils were analyzed for native fixed NH4, ammonium-fixing capacity, exchangeable K, and organic matter content. Ammonium fixation decreased with proximity to the surface whereas exchangeable K and organic matter increased. Adding KCl to Sceptre subsoil to increase the exchangeable K decreased NH4 fixation approximately in proportion to the amount of KCl added. Destruction of organic matter prior to NH4 fixation increased the amount of NH4 fixed, the increase being greater the higher the organic matter content of the sample. The decrease in NH4 fixation with proximity to the surface was due to potassium ion and organic matter content.